Saturday, August 11, 2012

Sweet Potato Soup

Sweet Potato Soup

Starchy vegetables have a long history of being used to make tasty and nutritious soups. Potatoes, pumpkin, butternut squash, zucchini, peas and beets are all main ingredients for soups all around the world. One of the most overlooked starchy vegetables is the sweet potato, which is a shame because it is full of flavor and goodness.

To be clear, I am talking about the sweet potato that is also sometimes referred to as a "yam". True yams are not often found in North America, but the confusion arises because there are two common varieties of sweet potato. First, there is a harder variety with a yellow interior, and a softer orange type. The orange ones that are sometimes called yams are my favorite, and they are best ones to use in this soup.

Sweet potatoes have a much more complex blend of starches and sugars, and because of this they benefit greatly from the carmelization that takes place in the roasting process. Their natural sweetness gets intensified and the overall flavor becomes richer. If it sounds like it will turn this recipe into a dessert, don't be fooled: even savory flavors get better when roasted.

To start making this soup, preheat your oven to 400 degrees Fahrenheit. Clean two or three large sweet potatoes and poke some holes in them with a steak knife or something similar. (Don't peel them.) Place the sweet potatoes in a baking dish and roast them for about an hour or so. They'll be soft to the touch when they are done, and they will probably be leaking an orangey liquid. Let them cool, and then peel the skins off (they will come off very easily if they are done.) You can roast the sweet potatoes ahead of time and use them later, or you can start the next process when you pull them out of the oven.

The next step is to thinly slice a large onion. Heat up a small amount of butter and olive oil in your soup pot and add the onion and a bit of salt. Slowly cook the onions until they become golden brown, but don't allow them to burn. The darker the onions get, the more they are getting carmelized, just like the sweet potatoes. This will really enhance the flavor of the soup. (Note: if you like, you can add a few cloves of garlic for even more flavor.)

Chop up the cooked sweet potatoes and add them to the pot. Mash them up a little, then add about 4 cups of chicken stock, or whatever broth you prefer. Bring the soup to a boil, then reduce and cook until it reaches a desirable consistency. Use an immersion blender to puree the soup. Add up to half a cup of heavy cream, and a dash of nutmeg, and you're done!